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MD5 To Be Considered Harmful Someday
Effugas writes "I've completed an applied security analysis (pdf) of MD5 given Xiaoyun Wang et al's collision attack (covered here and here). From an applied perspective, the attack itself is pretty limited -- essentially, we can create 'doppelganger' blocks (my term) anywhere inside a file that may be swapped out, one for another, without altering the final MD5 hash. This lets us create any number of binary-inequal files with the same md5sum. But MD5 uses an appendable cascade construction -- in other words, if you happen to find yourself with two files that MD5 to the same hash, an arbitrary payload can be applied to both files and they'll still have the same hash. Wang released the two files needed (but not the collision finder itself). A tool, Stripwire, demonstrates the use of colliding datasets to create two executable packages with wildly different behavior but the same MD5 hash. The faults discovered are problematic but not yet fatal; developers (particularly of P2P software) who claim they'd like advance notice that their systems will fail should take note."
I can only hope I live that long.
Aha! So it was MD5 and not MP5...
The owls are not what they seem
By examining the MD5 hash using a sophisticated Fourier schema followed by deconvolution with a bit binary-inequal collision analysis, it is quite obvious I have no freaking clue what this stuff is about.
I am glad somebody does.
No trees were harmed in the composition of this; however, numerous electrons were inconvenienced.
Two files with the same MD5 hash at once. Aaw yeah.